Traffic control system



Sept- 19, 193 9- J. o'D. SHE'HERD 2,173,596

` TRAFFIC CONTROL SYSTEM Filed July l, 1936 v 5 Sheets-Sheetl l JWM@ SIG/VAL $710 TIO/V6` Aff pf @l Oz @f f gang. MS

ST5@ 5 /57 /zqL s INVENTOR Sept- 19, 1939. J. oD. SHEPHERD l 2,173,596

TRAFFIC CONTROL SYSTEM Filed July 1, 195e 5 sheets-'sheet 2 b 05 To OTHER Sla/VAL smT/o/vs maA www l Sept. 19, 1939. J; o'D. SHEPHERD 2,173,595 w TRAFFIC CONTROL SYSTEM Filed July 1, 193e 5' sheets-sheet s 45o 46/ Y v 484 48g 46g T0 OTHER SIGA/HL 5 TAT/ONS STE/'57,4 454 47] STEEB WIIVNTOR J. O'D. SHEPHERD TRAFFIC CONTROL SYSTEM Sept. 19," 1939.

Filed July 1, 19.36 5 Sheets-Sheet 4 -w ya FIG. 5

70 OTHER` 5/6`NIL S TA TIONS INVENTOR FIG. 7

s ePt- 19, 1939- J. o'D. SHEPHERD 2,173,596

TRAFFIC CONTROL SYSTEM Filed July 1, 1936 5 Sheets-Sheet 5 'w Flan om f1 -fH e lo Patented Sept. 19, 1939 UNITED STATES PATENT OFFICE 21 Claims.

My invention relates to control systems and particularly to signal systems for controlling the flow of trame along streets and highways by means of signalling devices at intersections.

V One object of my invention is to provide improved means for controlling traffic along a street having a plurality of intersections in such a manner that the interference from traffic on cross streets is reduced, thereby increasing the eiciency 1o of vehicular movement along it.

Another object of my invention is to provide improved means for effecting the continuous movement of trafic in groups or waves in such a manner that a vehicle can move from one end of a street to the other without having to stop due to tramo flowing on cross streets, and by means controlled from a central point to change the times of operation of the signals at the plurality of intersections so that at other times a 20 vehicle can move Without stopping in the other direction.

Another object of my invention is to provide improved means whereby the traflic signals at street intersections throughout a city can be adjustably timed with respect to each other and the relative amounts of stop and proceed indication required by the individual intersections, and by means controlled from a central point to change the timing of the signal indications at each intersection with respect to those at the other intersections and the relative displays of stop and proceed indications.

Still another object of my invention is to provide improved means for controlling the signalling system from a central point sothat the signals at the plurality of intersections can be suspended from their normal operation and made to display a stop indication as might be desirable during a fire, or to flash yellow indications in all directions to indicate caution during light traiic hours, or to shut the signal system down, or to change the operation of any particular signal individually without disturbing the operation of other of the signals.

There are other. objects of my invention which, together with the foregoing, will be described in the detail specification which is to follow.

Briefly, the fundamental operation of the pincipal embodiments of my invention requires a rotary contact means at a central station, trunk conductors between the central and each of a plurality of signal stations at street intersections and a rotary contact means at each signal station, with means to cause these rotary devices to rotate in synchronism once each complete cycle of the signal operations. A second or signal contact means is provided at each signal station which is arranged to be operated to change the signal indications under control of the aforementioned rotating means at predetermined times 5 within the period of its rotation in such a manner that a complete cycle of signal indications is effected once yeach revolution of rsaid rotary contact means. The times at which the second or signal contact means is operated is adjustable so that the operation of signals at each signal station can be adjusted individually to the traffic ow requirement at the intersection under its control. By means which will be described in detail, operation of control means at the central station will cause the second contact means at each signal station to be operated at other predetermined adjustable times within the period of rotation of the synchronous rotary device. A third Contact means is provided with certain embodiments of my invention which turns olf the signals, turns them on', causes them to give particular combinations of indications and selectively controls the operation of the second contact means to change the signal operations within each traflc cycle.

'I'he secondary and tertiary contact means at each signal station are shown by the drawings to be stepped around by means of pawls and ratchet wheels, and they, together with the primary contact means, comprise cam wheels mounted on rotary shafts with electrical contacts associated therewith and operated thereby. The shaft at the signal stations which revolves in synchronism once each cycle is herein termed the sequence shaft, and the cam members attached thereto herein are commonly designated A in all of the drawings pertaining thereto, the secondary shaft is herein termed the signal shaft and the cam members attached to it are commonly designated B, and the tertiary shaft` is termed the reset shaft and the cam members attached to it are commonly designated C. The central station shaft is commonly designated D. These letter designations represent the functional correspondence between the shafts in the several drawings of the various embodiments of my invention.

The term rese as broadly used herein with respect to the signal operations ydesignates a particular manner of operation of the signal lamps, or particular ones thereof. The operation of them cyclically at particular times in a cycle is considered one reset,l at other times in each cyclev another reset, burning certain of them steadily another, ashing certain of them another and discontinuing them from operation still another. Other signal lamp operations can be secured, as will be understood, and these would be still other resets. The term operation as related to the several types or manners of operation of the signal lights is considered synonomous with the term reset, as set out above, in certain of the claims covering my invention.

Referring now to the drawings which comprise Figures 1 to 11, inclusive, I have shown, by means of conventional diagrams, the apparatus and circuits for carrying out my invention.

Figure l shows the central and remote station apparatus for one embodiment of my invention.

Figure 2 shows the type of cycle or combinations of signal indications for which the apparatus and circuits of Figure 1 are arranged, it being only one of a large number of types of cycles which I may elect to use.

Figure 3 is another embodiment which provides means for securing special operations ci the signals such as an all stop condition as might be required during a fire, an all caution condition which might be desirable during the times of day of light traflc density, and remote shutdown.

Figure 4 is another embodiment showing means for giving the features provided by Figure 1, means for securing an entirely different ratio of stop and go indications for certain resets or changes of signal operations and means for selectively resetting the signals at each signal station individually and independently of the setting of the signals at other signal stations.

Figure 5 shows one means for employing motor driven rather than step-by-step apparatus at the signal stations.

Figure 6 shows a clutch arrangement which I may elect to employ at the signal stations in conjunction with the embodiment shown in Figure 5.

Figure 7 is one form of speed change mechanisrn which I may elect to employ in connection with Figure 5.

Figure 8 shows means whereby the signals can be reset by employing contact members associated with the speed change mechanism shown in Figure '7.

Figure 9 shows means whereby the signals can be grouped so that each particular group can be reset independently of other groups.

Figure 10 shows means whereby the signal shaft is revolved mechanically by means associated with the sequence shaft.

Figure 1l shows means whereby the signal operations at particular intersections can be changed or the operations discontinued without changing the operations of the signals at other of the intersections.

In Figure 1, an adjustable speed motor |00 drives through suitable gearing a shaft represented by designation D towhich is attached two discs or drums, hereinafter termed drums. Drum I0| has a toothed periphery operating in conjunction with a contact making member |04 in such a manner that during one revolution the circuit through said contact member is opened and closed fifty times, this number being arbitrarily taken for purposes of explanation. Drum |02 likewise is attached to the above mentioned shaft and has suitably located on it a member or pin |01 which operates in conjunction with contact means |03 in such a manner that once each revolution of the shaft the circuit through the contacts is transferred; that is, the contacts which are shown closed are opened and the open ones closed. It is the purpose of drum |01 to send out a series of 50 impulses for each cycle of the traic signals and drum |02 changes. the circuit over which said impulses are transmitted once each cycle to effect and maintain synchronism of the apparatus at the plurality of signal stations as will be described. A cycle as used herein represents a complete change of traic signal lamps from a particular display condition through the Various other signal lamp displays or phases back to the original one.

At each signal station a shaft represented by vdesignation A has ve drums, through ||5 inclusive, located on it, each drum having one or more adjustable pins suitably arranged around its periphery which operate in conjunction with contact or switch means, such means associated with drum I is designated la. This shaft and the drums thereon are driven through one revolution each cycle by a stepping magnet operating in conjunction with a toothed or ratchet wheel, not shown. Such stepping arrangements are widely used in the telephone, supervisory control and other arts and description of the details of them are omitted. As employed herein, when the magnet |l| attracts its armature yan attached pawl is positioned against the ratchet wheel in such a manner that when the circuit to the magnet is opened the armature and pawl will spring back and advance the ratchet wheel, the shaft and the several drums thereon one step. The ratchet wheel has fifty teeth and Vconsequently makes one revolution for each fty operations o-f its associated stepping magnet. The stepping magnet at each signal station receives impulses simultaneously from contacts |00 at the central station and consequently the aforementioned drums at the central and each signal station operate in synchronism, making one revolution for each traic cycle. The circuit for effecting this can be traced from central station power terminal |08, which is connected to a suitable source of electrical energy, through contacts |04 which are intermittently operated as described, through the normally made contacts of |03, trunk conductor NI, the normally made contact of Ila associated with drum the back contact of relay |66, the winding of stepping magnet Ill, common return conductor PI to the other power terminal |09. The impulses over this circuit will result in the drums through |I5 being stepped around once each cycle.

For one and only one of the fifty positions of the shaft A for each cycle the pin on drum will cause its associated contact means Illa to transfer the circuit through it so that the impulse circuit for the stepping magnet will be transferred from trunk conductor NI to trunk conductor MI This is for the purpose of synchronizing the signal station shaft A and drums with those at the central station. Assuming that the signal shaft A is out of synchronism with the central station shaft, when the contact means la transfers the stepping circuit from conductor NI to MI the signal station drum will stop since conductor Ml is connected to the normally open contacts of |03. When'pin |01 operates contact means |03 an impulse is sent out over conductor MI to the signal stepping magnet, causing the signal shaft A. to be stepped around one position, thereby permitting the restoration of switch Illa to complete the aforedescribed normal stepping circuit for the stepping magnet. These arrangements, which are identical at each signal station, result in the shafts A andthe drums thereon at all of the signal stations revolving in synchronism, but if for any reason one of them falls out of step with the others it is` subsequently automatically restored to synchronism.

Each signal station has a secondary shaft designated B with driving means similar to that of the other shaft thereat, said driving means revolving the shaft in six steps. It has seven drums, each with adjustable pins .and contacts associated therewith in psuch a manner that a circuit is completed through said contacts for particular ones of the six positions which the drum can occupy. 'Ihese drums are termed the signal drums and the shaft B the signal shaft. Drums |3| through |36, inclusive, control the circuits to the signalling means, each drum being associated with one of the six signalling means shown. While any suitable signalling meansv can be employed with my invention, for the purpose of describing it signals having a set of three colored display lenses facing north and south designated N--S and another set facing east and west designated E-W are assumed, each lens having an independent lamp `bulb back of it in such a manner as to display when lighted the commonly used red, yellow and green signals to traic on the two. streets comprising an intersection. It is to be understood that the compass directions mentioned above are assumed for illustration to differentiate between the two directions of intersecting streets and that any other suitable means and arrangement of signalscan be employed with my invention. .i In the position shown for the drums-on Ashaft B a circuit can be traced from terminal |98 of a suitable local power supply at the signal station, the closed contacts associated with drum |36 to the E-W green signal lamp to the other power terminal |99. A similar circuit can be traced through the N-S red lamp through contacts associated with drum I 3|. This condition represents the first or initial phase of the traflic cycle. In the second position of the drums circuits can be traced through the N-S red lamp and the E-W yellow one. In the third position both yellow lamps will be lighted, and in the fourth the N-S green and the E-W red displays will be shown. The fifth position will illuminate the N-S yellow and the E-W red lamps and in the sixth position yellow will again be displayed in both directions. The particular combination and sequence of lamps lighted during one cycle is known to the art as the type of traiiic cycle. The one assumed for this description is only one of a large number which can be secured with my invention. It is graphically shown by Figure 2 which indicates the color combination for each cf the six phases of the cycle, but not the length of the display of each, which will be considered below. A greater or smaller number of independently operable signals can be used in which case a greater or smaller number of drums similar to I3I through |36 may be employed. It is to be understood that the position of the pins on drums |3I to |35, inclusive, can be changed, or a greater or smaller number can be employed on each of the several drums to change the type of cycles or combination and sequence of lamps lighted during each revolution of the signal shaft B.

N-S red is displayed for both the iirst and second steps of the cycle. In the traffic signal art it is not considered good practice to have signals to flicker, so that contact means associated with signal drum |3| has a shoe |3|a connected to it in such a manner that when the drum is stepped from the first to the second position the pin in the second position comes under the shoe before the one in the iirst position moves out from under it. 'Ihis prevents the circuit through the contacts from being opened even momentarily between the two positions. The other drum contacts are similarly equipped or other means to effect this end may be employed.

The signal shaft and attached drums are stepped around by impulses from sequence drums I'I and |I5. The circuit for effecting this can be traced from power terminal |98, contacts of drum lli which are closed in iive of its positions by ve pins placed in particular positions around it, the normally made contact of drum |31, through the winding of stepping magnet |12 to the other power terminal |99. The signal drums therefore are stepped around five positions, E through 5, inclusive, during each revolution of the sequence drums by the circuit described. In position 6 the contacts associated with drum I3'.l transfers the stepping circuit from drum IIQ to drum I I5. 'I'he latter drum has only one pin, and when it causes its associated contacts to be operated the signal drums are stepped into position I which represents the beginning of the tralic cycle. This arrangement is the same in principle as described above for maintaining the sequence drums in synchronism with those at the central station.

The pins on drums III, |I4 and |I5 are adjustable around the periphery of their respective drums and each may be placed in any one of fifty positions thereon. Any suitable means for effecting the desired result of having contacts with adjustable means to cause the operation of said contacts at any desired position or time during the revolution of the sequence drums can, be employed. One form would be to have fifty tapped holes spaced equally around each drum with the pins having screw threads toenable them to be placed around the drums as desired.

The location of the pin on drum I|I controls the phase relation between the sequence drums at each signal station and the control drums at the central station. The pin on drum I I 5 at each signal station controls the start of the traic cyclefor that station by completing the circuit tc stepY the signal shaft B and drums into the first position. This pin can be located with any desired one of fifty angular relations to the pin on drum III. Since the pin on drum I| I at all signal stations simultaneously operate their synchronizing contacts and therefore cause the sequence drums to rotate in phase, the cycle at each signal station can be made to begin at a predetermined adjustable time with respect to the beginning of it atthe other signal stations as determined b y the location of the pin on drum IIE with respect to the one in |I| at each signal station. Likewise, the locations of pins on drum II4 are adjustable and control the beginning and duration of the other five phases in the traffic cycle.

My invention, therefore, enables the relative times of signal displays at each signal station to be adjusted by the pins on drum I I4 to the traffic requirements at that particular intersection and also by properly setting the beginning of the cycle at each station along a street by positioning the pin on drum H5, traic can be coordinated along a street or series of streets.

The' Coordination of signals whichl will effect 75 an efficient movement of traffic in one direction may not be .proper for the most effective movement in the other. In certain cities and in portions of others there is a. preponderance of traffic flow in different directions at different. times of the day. The generally heavier.. movement toward the business center in the morning and away from it in the afternoon is illustrative of the usual condition experienced. Traflic signals adjusted properly to care for Vthe morning flow may not be satisfactorily timed with respect to each other to eiiciently handle the outward movement at night. Means are shown by Figure l whereby the setting of the signals with respect to each other can be changed from the central station. Operation of switch |06 will cause relay |56 to be operated by an obvious circuit, including trunk conductor Q2. The operation of this relay will transfer the stepping circuit for stepping magnet I 1| from control of contacts associated with drum I I I to those associated with drum I I2, said circuit extending through the front contact of relay |56 and the back contact of relay |65. The position in which the sequence drums will now be synchronized depends upon the position of the pin on drum ||2, which can be placed at any desired angle with respect to the pin on drum I I5, which, as stated above, controls the beginning of the cycle. This angle can be different for each signal station so with relay |66 operated the signals at each of the signal stations will be operated to effect a new coordinated control of traic. This change of relative signal timing is, as stated above, known to the art as resetting.

Means for securing a third reset is also shown by Figure 1. If both switches'l05 and |05 are loperated they will, over obvious circuits, including trunk conductors QI, Q2 and PI, cause the operation of both relays |85 and |86. Their two armatures in their operated positions transfer the stepping circuit for magnet I'II to the con- 'tacts associated with drum H3, said circuit extending through the front contacts of relays |65 and |66. Inasmuch as the synchronization of the drums is now determined by the position of 'the pin on drum |I3, which is adjustable with respect to that on drum I l5, a new setting of the signals at the various signal stations has been effected. Extension of this principle will permit the employment of still other resets.

In practicing my invention I may elect to group the signal stations so that particular groups of them can be reset. In order to effect this I would employ a separate trunk conductor to each of the groups of signals to be reset, together with a separate key similar to |05, so that when this key is operated relay |66 at the particular group of signal stations Will be operated and the signals at these stations will be reset without disturbing the setting of the other signals. This grouping of signals can be employed for other resets, in which case I would not be limited for the other resets to the same grouping as employed for the first reset. That is, if I should provide two groups of signals, with arrangements to reset the second group without vdisturbing the setting of the rst, I could also arrange them into a third group for resetting purposes, said third group could comprise certain of the signalsA in the first and second groups. These arrangements are shown by Figure 9, which includes only those portions of Figure l involved in changing the setting of the signals with relation to each other and keys |05 and |06 and relays |65 and |66 are the corresponding elements'shown in the latter iigure. The resetting relays of another one of the signals in this group are designated |65 and |66. A second group of signals are indicated by reset relays |65A and IBSA, and ||55Al and IBSA. Resetting of thesignals in the first group is accomplished by the selective operation of keys |05 and |06 and, in an identical manner those of the second group are reset by the operation of keys |05A and |06A. These several keys can be independently operated so the two groups of signals can be independently reset as desired. Twoadditional reset keys designated |85B and |06B are shown with conductorsQIB and QZB extending to various of the signal stations. The reset relays are provided with a secondaryy Winding and the latter Winding of certain of the relays is connected to conductors QIB and Q2B. Let it be assumed that all of the signals are normally operating with all of the reset keys in their open positions. Operation of key ||35B` will result in the operation of relays |65, |66 and |56A, the circuits therefor extending from power terminal |08, key |S5B, the secondary windings of said relays, common return conductor PI to the other power terminal |09. This results in the. signals at the stations corresponding to these relays being operated in the reset controlled by each of said relays, respectively. The release of key I05B and the operation of key |05 B will effect similarly resetting at and only at the stations controlled by relays |65 and |65A. Operation of both keys |05B and |06B will result in the signals associated with relays |55 and |66' being operated in the reset corresponding to said pairs of relays in their operated position, whereas relays |55, |555A and |56A will cause their associated signals to operate in the reset corresponding to the operated positions of said relays. It is to be understood that in practicing my invention I may arrange the signals in any desired grouping by appropriately connecting the primary and secondary windings to the circuits to the resetting keys. It also is to be understood that by similar means more'th'an four signals can be so operated and more than two groupings employed.

The signal shaft B is shown as electrically operable by means of a separate stepping magnet I'I2. Without departing from the scope and spirit of my invention, I could employ mechanical means for operating said signal shaft. One arrangement for effecting this is shown by Figure 10. Drums I I4 and I|5 are omitted fromv shaft A and adjustable cams I'I'd and I I 5 are substituted. Cams H4 comprises an assembly of ve discs each with a single cam face thereon, the discs being arranged so that they can be positioned independently in such a manner that their respective cams will bear a desired circumferential relation t0 shaft A. Lock nut |86 is provided to lock said discs in the desired position, although I may employ other appropriate means for adjusting and locking said discs. Drum i3? on shaft B is omittedin this embodiment and ratchet wheel |31 is substitut-ed therefor. A rod 585 is provided with two bearings IBI and |82, suitably mounted, so that said rod can be moved longitudinally. A spring |85 tends to maintain said rod in the position shown. Rod |80 terminates in a cam follower |8I provided to operate in conjunction with cams I I4 so that as shaft A revolves the rod |80 is given a reciprocating motion at particular times dependent upon the position of the cam faces. A pawl |84 is pivoted to a collar |83 attached to rod |80 and is maintained in contact with ratchet wheel |31( by spring |88. When rod |80 is forced to the-right by a cam face of H4 the pawl is normally positioned with respect to one of the teeth on |31', so that when said cam face moves out from under the follower and spring |85 pushes rod |80 to the left, the pawl normally engages a tooth and advances shaft B one position, or asixth of a revolution. One tooth is omitted from this ratchet wheel in the sixth position so that these means described will advance the shaft to said sixth position where they become ineffective. A second ratchet wheel |31 is provided on shaft C with a single tooth in the sixth position and the disc H5 has a single cam. 'Ihis cam can also be circumferentially positioned as desired on shaft A. By means of the rod assembly shown, which can be identical with' that associated with cams ||4, shaft B will be aclvanced from the sixth to the first position provided the cam on disc ||5' operates the rod assembly while the tooth on wheel |31" is in the sixth position. This assures a predetermined operating relation between shafts A and B, since the cams ||4 cause shaft B to be stepped from positions one through i'lve but not from the sixth into the first, which latter operation is effected by the cam face on disc H5. By suitably positioning the discs H4 and H5 shaft B can be rotated in steps at any desired times during the rotation of shaft A.

I may elect to employ a greater or smaller number of phases or different combinations of lighted signal lamps each cycle than shown, in which case I may arrange the drums and ratchet wheel on shaft B so that they would occupy a greater or smaller number of positions each revolution of said shaft. This would necessitate the employment of a greater or smaller number of pins on drum I I4 to provide in conjunction with drum |15 the proper number of impulses to step shaft B through one revolution for each revolution of shaft A. I may also-elect to arrange to have shaft B stepped around two revolutions to one of shaft A.

The modification or embodiment of my invention as shown by Figure 3 provides an alternate method which I may employ in connection with resetting signals and also shows means whereby certain special operations of the signals can be secured. The apparatus at the central station is identical with that shown in Figure l except additional contacts are provided in connection with the synchronizing drum 302 at the central station and one resetting switch 305 is employed instead of two as shown in Figure 1. At each signal three sets of drums are provided, each set being attached to an individual shaft represented by the designation A, B and C, respectively, those attached to shaft A corresponding to the sequence drums and those attached to shaft B corresponding to the signal drums in Figure l, whilev the third set attached to shaft C are used in connection with resetting the signals. These latter drums can occupy any one of six positions and their form is somewhat different from those previously described. Instead of having pins to operate the associated contacts, the drums are in the form of cams with faces which in certain positicns cause their associated contacts to be operated by means of cam followers. As shown in Figure 3, drum 343 closes its associatedcontacts in positions i, 2 and 3, drum 344 in position d., drum 345 in position 5, drum345 in positions 4 5 and ii and drum 341 in position 6. Drums 34| and 342 are employed to control the position in which the sequence drums are synchronized, with the operating face of the cam of drum 34| in positions 2 and 3 and 342 in position 3.

Drums 33| through 336, inclusive, correspond in purpose and operation with drums |3| through |36, respectively, and control the lighting of the signal lamps provided the reset drums are in positions I, 2 or 3, resulting in the contacts associated with drum 343 being closed. Drum 331 controls the proper sequential operation of shaft B with respect to the sequence drums in a manner identical with drum |31 of Figure 1. During the normal operation, shaft A is stepped around one revolution per trai-lic cycle, and from the position of adjustable pins on drums 3|4 and 3|5 operating associated contacts, the signal drums on shaft B are stepped around in proper phase relation with reference to shaft A to control the operation of the signal lamps, the circuits therefor passing through contacts associated with drum 343. The detailed description of these operations was covered above in connection with Figure 1.

The reset drum is shown in position If it is desired to operate the signals for the second reset, key 305 is moved to close contact a, and a circuit can be traced from power terminal 308,

contact b of switch 303, contact a of key 305, trunk conductor Q3, winding of stepping magnet 313, the normally made contact of drum 341, common return trunk conductor P3 to power terminal 309. The stepping magnet will position its pawl and when key 305 is restored it will release and advance the reset drums to position 2. Key 305 can be repeatedly operated to advance the reset drums to any one of the first five positions.

In position 3, drum 341 transfers its contacts,

thereby opening the stepping circuit just described, and repeated operation of key 305 will not advance the drum to position The above operations assume that the central station drums are in some position other than 50, the synchronizing one. When it reaches the latter position switch 303 is operated and if key 305 is moved to close contact b, a circuit can then be traced from power terminal 309, contact a of switch 303, contact h of key 305, trunk conductor Q3, winding of stepping magnet 313, the upper contact associated with drum 341 which is in position 6, trunk conductor M3, contact c of switch 303, contacts 304 to the other power terminal 308. When contacts 304 are opened, magnet 313 will release to advance the reset drum to position l, from whence it can be stepped by means previously described. Controlling the reset drum by operating key 305 to close one of its contacts for five positions of the former and for the sixth by closing it to the other position, permits the desired position of the reset drums to be assured. Position 6 of the reset drum disconnects the signal lamps for shutting down the system as will be described below. In shutting it down, key 305 would be repeatedly operated which would cause the drums to reach position S and stop, subsequent operations of the key being made to as- Sure that the reset drums at any signal stations which have fallen out of' step for any reason also reach this position. When the system is started up again the opposite operation of the key with drum 302 in position 50 will cause all reset drums simultaneously to step to the first reset position. In practicing my invention, I may have a counterpart of the reset drums or other appropriate means at the central station to indicate the reset position in which the signals are operating at any time. The position of the central station drums also could be shown .to enable the proper operation of key 305 in relation thereto.

In position of the reset drums, a circuit can be traced from power terminal 300 through contacts 304, contacts d of switch 303, trunk conductor N3, the normally made contact associated with drum 3||, the normally made contact of drum 34|, the winding of stepping magnet 31|, common return trunk conductor P3 to the other power terminal 309. Shaft A will, therefore, step around under control of the impulses from switch 304 until position 50 is reached at which time the stepping impulse will be transmitted over trunk conductor M3 in the manner described in connection with Figure l. If the reset drums are in position 2, the contacts associated with drum 3|2 are made effective by transfer of the contacts associated Ywith drum 34| to control the synchroization of thev sequence drums with respect to the central station control drums, and in the third reset position, the operation of the contacts associated with both drums 34E and 342 will cause the synchronizationof the sequence drums to be controlled by drum 3 i3. Inasmuch as the pins in drums 3||, 3|2 and 3|3. independently can be placed inany one of fifty positions around their respective drums, the signals at the plurality of the signal stations can be set from the central station with respect to each other for any one of three coordinated operations as controlled by the positionof the reset drums.

In the first three positions of the reset drum the signal lamp circuits are extended to the contacts of the drums onshaft B and the signal lamp operations are controlled by the pins on these latter drums 33| through 336, inclusive. In reset position 4, the contacts associated with drum 343 are opened and those associated with drum 344 are closed. This results in the red signal being displayed to traffic in both directions, the Vcircuits for effecting it being obvious. 'I'his reset can be used in the event of re or other condition where it is desirable to stop all trafc. In reset position 5, another special signal operation can be secured. The connections shown provide flashing yellow lights in all directions, as I might employ during hours of lighttrafc to indicate necessity of cautious voperation of vehicles. The circuits for effecting this operation can be traced from power terminal 399, the yellow signal lamps, the closed contacts associated with drum 345, conductor 362, the front contact of stepping magnet 31|, conductor 30| to the other power terminal 308. Each time the stepping magnet operates this circuit is closed, resulting in the yellow lamps flashing. Instead of employing contacts associated with stepping magnet 31|, I may elect to employ a serrated drum or disc, generally similar to 30|, attached to shaft A with contacts similar to 304 inserted between conductors 30| and 362.

In reset position 6 all signal lamps will be extinguished as is desirable for night conditions after traffic has been reduced to the point that signal operation is not necessary. lIhe circuit for the stepping magnet 312 for the signal drums is opened in this position by contacts associated with drum 346. It probably would be desirable to stop the central station drums at night when the signal system is shut down and this might result in the sequence drums at certain signal stations being left standing in such a position that the stepping magnets for the signal drums would have current flowing through them, except for the arrangement shown for opening the circuits to them by means of the contacts of drum 346. Inasmuch as the operation of the signal drums is not required in reset positions 4 and 5, the operating cam face of drum 346 is extended through positions 4 and 5 as well as 6, and the circuit to stepping magnet 312, therefore, opened for all resets except the iirst, second and third, for which it is necessary that the signal drums be revolved.

The particular combination of signal lamps lighted in reset positions 4 and 5 is shown for illustration and I may elect to use other combinations for these positions, either with steady or flashing illumination. In this connection I may employ additional contacts associated with drums 344 and 345 to secure the combinations which are desired. l

Inasmuch as the type of traffic cycle employed in a city rarely is changed, I may elect to use for the signal drums the cam type of drums shown on the reset shaft. This will require that the cam faces be designed to operate the associated contacts in the positions shown occupied by pins. The shoe shown provided with the contacts would, of course, not be required.

Mechanical operation of the shaft of the signal drums can be used with this embodiment of my invention by means described above in connection with Figure 1.

During certain times of the day and with certain traic conditions it may be desirable at particular intersections to disconnect the signals thereat from control of the central station apparatus and to manually control their operation. To this end switch 380 with a normally `open contact is provided, suitably mounted in the signal apparatus housing or in the form of a push button on a flexible cord. Operation of this switch causes stepping magnet 312 to be operated over an obvious circuit and when said switch is released the resulting opening of its contacts will cause magnet 312 to release, thereby stepping the signal shaft and drums to their next succeeding position. Repeated operation of this switch will cause the signal drums to be stepped through their several positions, causing the signals to be displayed through the successive phases of the trafc cycle, with the intervals for each phase controlled by the operation of said switch 360. It is to be understood that when manual operation is to be eifected a switch, not shown, will be opened to disconnect the signal station apparatus from the trunk conductors, shaft A will be manually moved if necessary to one of the positions in which there is no completed circuit to stepping magnet 312 and the reset drums will be in positions 2 or 3, or will be manually moved thereto if necessary. Restoration of the switch to reconnect the signal station apparatus to the trunk conductors will result in the signal station apparatus being synchronized and again operated under control of the central station apparatus. It is to be further understood that suspension of a signal from centralized control and operating it manually can be eiiected by similar means with other embodiments of my invention.

The embodiment of my invention shown by Figure 4 provides an alternative method which I may employ in connection with resetting signals, also shows means whereby any individual signal along a street can be reset without changing the setting of the other signals, and also discloses means whereby certain special operations of the signals can be secured. Atlthe central station is provided a step-by-step rotary selector of a type Ito in purpose to those shown in Figure 3.

commonly used in the telephone and other arts, which comprises banks of contacts 40|, 402 and 403 around which wipers aixed to a common shaft are stepped by means of stepping magnet 4&5. An interrupter 400 is driven by a speed adjustable motor or other adjustable speed driving means and provides electrical impulses which are employed to operate the central station selectors and also certain apparatus at each of the signal stations. Bank contacts 40| and associated wiper are employed in connection with maintaining the signal station apparatus in synchronism, bank contacts 402 and associated wiper in connection with suspending the impulses to the signal stations While the signals are being reset and bank contacts 403 and associated wiper are employed in connection with the resetting operation. These banks have twelve contacts and for thepurpose of describing the operation of this embodiment of my invention it is assumed that twelve impulses are employed for each traflic cycle although a number greater or smaller than this number can be employed in practicing my invention.

- When the interrupter 400 operates, a circuit can be traced from power terminal 408 through the normally made contacts of key 489, bank contact of selector 402, through the interrupter to a junction, at which point the current divides and a portion of it goes through the stepping magnet 405 to the other power terminal 409. This causes the magnet to attract its armature and position its pawl with relation to a ratchet wheel, not shown, on the common shaft to which the several central station wipers are attached. After a short interval the interrupter breaks" the above described circuit causing the stepping magnet to releaseand its associated pawl to advance the wipers from contacts to contacts I2. Contact I2 and-all of the contacts shown on selector 4522 either have a key connected to them or are directly connected by appropriate wiring to terminal 458. Further impulses .caused by the operation of the interrupter will result in the Wipers being stepped completely around their banks, said circuit being completed on each bank contact of Q02 through one-of the keys or they additional wires mentioned above.

At each signal station is a set of drums similar The sequence drums 4|2 through 42|, inclusive,V are fixed tc a shaft designated by A in the center of each drumsaid shaft being `stepped around one twelfth of a revolution each time the stepping magnet 47| releases. The circuit which operates this stepping magnet is traceable from the aforementioned .iunction at the lower terminal of the central station interrupter, a back contact of relay 404, trunk conductor N4, a normally made contact associated with drum 4| I, the winding of magnet 4'! common trunk conductor P4 to power terminal 4&9. The impulses from interrupter 400, therefore. steps the sequence drums on shaft A around in synchronism with the wipers at the central station, it being understood that said wipers being double ended revolve through 180 while the sequence drums revolve through 360. When the sequence drums reach position |,2 the pin on drum 4|| causes the circuit through the associated contacts to be transferred, thereby transferring the impulsing circuit for magnet 41| to trunk conductor M4 which is connected to a front contact of relay 404 at the central station. Relay 404 operates over an obvious circuit only when the wiper of selector 40| rests on contact Y erative.

|2. The operation of relay 404 causes trunk conductor M4 to be connected to the interrupter circuit and the next impulse therefrom reaches the stepping magnet 41|, causing it to advance the sequence drums to position from whence stepping will be effected by the previously described circuit including trunk conductor N4. If the sequence shaft gets out of synchronism it will be stopped in position twelve until the central station wipers reach the twelfth contact, at which point synchronism will be restored.

Only the signal drums on shaft B required in connection with the operation and control of the shaft itself are shown, those required for controlling the circuits to the signal lamps being identical with drums 33| through 336, inclusive, shown in Figure 3. Drums 433 and 430 control the proper stepping of shaft B to which drums similar to 33| through 336 inclusive, are attached. For the position of the reset drums on shaft C shown, a circuit for the operation of stepping magnet 412 which operates shaft B can be traced from power terminal 408, the contacts associated with drum 4|2, which are closed by the five adjustable pins around the periphery of said drum to cause ve impulses to be transmitted for each revolution of shaft A, a made contact associated with reset drum 45| which, for the purpose of this description is in the first position, the normally closed contact associated With drum 438, the winding of stepping 'magnet 472 to the other power terminal 49d. This stepping magnet, therefore, operates over this circuit to step the drums on shaft B through five of their six positions. In the sixth position the aforementioned contacts associated with drum 438 are opened and consequently the impulsing circuit described immediately above is made inop- When drum 4|3 reaches the position in which its pin closes the associated contacts a circuit can be traced from power terminal 49S, the closed contacts associated with drum M3, the other closed contact associated with drum 45|, the closed contacts of drum 439 which is in position 6, a back contact of stepping magnet M2, winding of same to the other power terminal 495|. 'Ihe stepping magnet will operate, break its own circuit, release and in so doing step shaft B with the drums attached thereto around to the rst position. In the normal operation of the system, shaft B will .always be in position 6 when this latter described operation takes place and the drum will be moved one step to position where the contacts associated with drum 430 are opened. If, however, drum 4| 3 closes its contacts when shaft B is in other than position or the stepping operation of magnet 422 will be repeated and shaft B will step around to position rapidly by magnet 472 interrupting the circuit described, said circuit being broken by the contacts of 439 only when the shaft reaches position one. Recapitulating, the normal stepping circuit for magnet 412 is operative for five positions of shaft B, but in the sixth, a circuit from the contacts associated with drum 4|3 is required to step shaft B from the sixth to the rst position. This assures that shaft B operates in proper steps with respect to shaft A, inasmuch as once each revolution shaft B is synchronized with shaft A, and if they are out of synchronism, shaft B will be rapidly stepped around into synchronism.

The above described circuits are completed if the reset shaft C is in position one, and the contacts associated with drum 45| are closed. In

position two, these latter mentioned contacts will be open due to the design of the cam face of drum 45 i, and the contacts associated with drum 452 will be closed. This connects the stepping and synchronizing circuits for magnet 412 with drums 4l!! and 4l5, respectively. Consequently, for the second reset, the stepping and resetting o-f shaft B are controlled by the adjustable pins on these latter drums, which can be located in entirely different positions from the corresponding pins in drums 4l2 and 443. Therefore, for the second reset, both the beginning of the cycle and the relative times of signal displays of the signal lamps can be adjusted by suitably locating the pins on drums 4l4 and 4i5 to be entirely different frorn the beginning of the cycle and relative displays provided in the first reset. In practicing my invention this embodiment would have merit over that shown in Figures l and 3 since it might be desirable to adjust the relative times of proceed indication on the N-S .and E-W streets for the variation in traffic movement at different times during the day, as well as to reset the signals with respect to each other. A third reset can be provided controlled by drum 453 in its third position, connecting the stepping and synchronizing circuits to two other drums, not shown, on shaft A, and still other resets likewise can be provided.

Shaft C, upon which are mounted drums 45| through 459, inclusive, is stepped by magnet 413 as it releases. As with stepping magnet 412, upon operating it opens a back contact, so that when a circuit is completed through said contacts, the stepping magnet operates as a vibrator stepping shaft C around until said circult is opened as will be described. Shaft C also has mounted on it drums similar to and with the same purpose as drums 343 through 345, inclusive, not shown. The position of this shaft determines which reset is effective in positions one through three, inclusive, and the combination of lamps lighted, if any, for positions four, ilve and six. This arrangement is set forth clearly in Figure 3. A drum similar to 345 can be provided so that in the off and special reset positions the stepping magnet circuit can be opened in the obvious manner as shown with the stepping magnet in Figure 3, to stop the operation of magnet 412.

Means for selecting the reset position from the central station now will be described. Assume the signal system is operating in the first reset as shown, and it is desired to operate it in the second one. Key 482 will be operated which opens the circuit to point 2 of bank contacts 402 and connects power from terminal 408 to point 2 of bank contacts 403. When the wipers reach point 2 they will stop and the operation of the sequence shaft at each station will be interrupted since there is now no power encountered on this point by the wiper of bank 402. Power from terminal 408 will be encountered on point 2 of bank 403 by the associated wiper, which extends this circuit over trunk conductor 04 to the contacts associated with drums 4l6 through 42l, inclusive. The single pin on each of these drums is in a different position from the remainder, and only one set of these contacts is closed at any one time. Since the drums were stopped in position 2, contacts associated with drum 4I1 will be closed since the pin thereon is in position 2. The above mentioned circuit over trunk conductor 04 will be extended through these latter contacts, contacts associated with drum 455, the

signals in accordance with the settings for the 1.

second reset. It is obvious that shaft C will be stepped around to reset position two from whatever position it was last resting, since the cam face of 455 maintains its contacts closed for all positions except 2, and stepping magnet 413 will continue to operate as a vibrator to step the shaft and drums until this position is reached. After a suicient interval has elapsed to assure that the reset drums at all signal stations have reached position 2, key 482 is restored, whichV permits the normal stepping impulses to be transmitted to the plurality of signal stations and the signal lamps thereat will be operated with the beginning of the cycle and the relative times of signal displays at each station individually operating in accordance with the traffic flow requirements ofthe intersection for the second reset.

Other resets are secured in the same manner as described for the second reset by operating the desired key 48! through 486, inclusive. Each will stop the. sequence drum so that one of the contacts associated with drums 416 through 420, inclusive, is closed, resulting in a circuit being extended to stepping magnet 413 Via the contacts associated with one of the drums 454 through 459, inclusive, thereby causing shaft C to be positioned for the selected reset. The selecting drum on shaft A for the third reset has been omitted, but it operates in the same manner as drums 4|6 through 420, inclusive, to effect the selection of the third reset. Other resets, likewise, can be provided if considered desirable in practicing my invention.

I may elect to check once each cycle the reset position in which the 4signal system is operating, and key 488 is provided for this purpose. When it is operated, it maintains power from terminal 408 connected to the upper contact of interrupter 400. If the system is operating in the second reset, for example, key 482 would, with this arrangement, be left in its operated position. thereby maintaining power connected to contact 2 of bank 403. Impulses will be continued with key 488 operated, so the wipers at the central station and the sequence. shaft at the signal stations will continue to be stepped around, and an impulse will be transmitted to the signal stations each cycle during .the interval of position 2, said impulse passing over previously described circuits including trunk conductor 04, contactsof drum 4| 1 to the open contacts of drum 455, which is in position 2. If, however, the reset shaft is not in position 2, this circuit will be extended through contacts of 455 to operate stepping magnet 413 to step it to this position. Inasmuch as the operation of stepping magnet 413 could be made very rapid, I may elect to dispense with selector bank 402 and wiper and the connections thereto, in which case the resetting operation initiated by the operation of one of the keys 48| to 486, inclusive, would occur during the interval of one position of the wipers and sequence shaft.

The six resets provided in this embodiment of my invention are shown as being selected by operating the six keys mentioned above. This leaves ve terminals on selector banks 402 and 403, it being understood that the twelfth terminal is used for synchronizing the central station selector with the sequence drum at the signal stations. These terminals can be employed for other purposes as will be described, but if not so employed those of selector can be directly connected to power terminal 408, as shown, so that the interrupter circuit will be maintained while shaft A is in positions corresponding to these terminals. I may elect to employ certain of these terminals in order to reset the signals at each station independently of those at the other signal station. This will permit individual signals located at minor intersections to be turned oii in the evening or other operations thereof secured without disturbing the remainder of the signals. Drum 42l is provided with one pin in position I 0 at this particular signal station. It is assumed that there are iive signal stations in the system and there is a key similar to 481 for each. If key 481 is operated, it will stop the central station selector and the sequence drums at the signal stations in position I0. This particular signal station will be the only one in which the contacts associated with drum 42| are closed in this position, and consequently at this station only will a circuit be traceable from power at terminal 408, closed contact of key 481, point I D of bank 403, wiper, trunk conductor 04, contacts of 42H, contacts of 459, stepping magnet 413 to the other power terminal 409 via common return conductor P4. This will cause the reset drum at this and only this signal drum to be stepped around to the sixth or off position. Restoration of key 481 will permit the remainder of the signals to operate in a normal manner with this particular signal turned off. Operating any other reset key will cause this signal as well as the others to be reset in accordance with the selected key.

With a twelve impulse system such as the one described I can, by a simple modification, selectively reset eleven signals individually in addition to the number which can be individually reset by the means described immediately above. This arrangement is shown by Figure 1l, which includes only those elements shown by Figure 4 which are required for this particular operation. Keys 48| and 486, bank and Wipers 402, stepping magnet 405, interrupter 400 and power terminals 408 and 409 are the correspondingly designated parts shown in the latter figure and are for the purposes and functions explained in connection therewith. Certain of the circuits from terminals of bank 402 are shown vacant but it is to be understood that each of these terminals has a connection to power terminal 408 either through key contacts or directly as shown by Figure 4 in order that a circuit to interrupter 400 is normally maintained throughout the revolution oi the wipers on shaft D. Another bank and wipers designated 403A is provided for the individual resetting of signals. All or particular terminals on this bank can be selectively connected to power terminal 408 by means of keys, of which three designated 4M, 495 and 49g' are shown. The circuits from keys 48! and 485 as shown by Figure 4 are eX- tended directly to the bank of 402 but in this embodiment of my invention these circuits are eX- tended through normally made contacts of keys 491 and 495, respectively, and the operation of key 48! or 49! will cause the wipers to stop on the iirst terminal of the banks, the operation of either 485 or 496 will cause them to be stopped on Jthe 6th terminal and the operation of 499 will stop them on the 9th in the manner which has been described. The wipers of bank 403A are connected' by means of trunk conductor R4 to contacts associated with an additional drum on shaft A at each of the signal stations, said drums at stations D, E and F being designated 42ID, 42H3? and MEF, respectively. Drum 42lD has a single pin in position i thereof, drum 42lE in position t and drum 42F in position 9, so that when the drums are in these respective positions the associated contacts are individually closed. in this embodiment of my invention I also provide an auxiliary drum on the reset shaft C at each of the signal stations, designated 458D, 45812' and 4581i', respectively, and a secondary winding and auxiliary back contacts on each of the stepping magnets 453D, MSE and 413 F. When drum 429D is in the first position a partially completed circuit can be traced from trunk conductor R4 through the contacts associated with said drum, contacts associated with drum 45SD, a back contact of 413D, the lower winding of stepping magnet 413D to power terminal 409 by way of common return conductor P4. A corresponding circuit can be traced at stations E and F when the shafts thereat are in positions t and 9, respectively.

It is to be remembered that the shafts A at all stations are stepped around in synchronism and corresponding phase relation with shaft D and the wipers at the central station by means described in connection with Figure 4. Assume that the signal system is operating in the normal or 1st setting as controlled b-y shaft C being in its 1st position, and it is desired' to reset signal 42! alone. Key 40l is operated which, by means already described, causes shaft D at the central station and shafts A at the signal station to be stopped in position l. A circuit can then be traced from power terminal 498, the closed contact of key 495, terminal l of bank 403A, the wiper thereof to trunk conductor R4 to the now closed contacts associated with drum 42l to complete the previously described partial circuit, which results in stepping magnet 413D operating and releasingV repeatedly and thereby stepping shaft C until the contacts associated with drum thereat will not be closed since the pins on said drums are in positions other than the 1st. Restoration of key im will cause the signals to continue to operate in the manner previous to this resetting, except those at station D, which will operate in the manner controlled by the reset drums thereat occupying position 5. In a similar manner, the signals at station E can be reset without disturbing the setting of the remainder by operating key 49S, and those at station F by operating key 49S. It is contemplated that the auxiliary reset drums similar to 458D will be adjustable circumferentially on shaft C so that the individual signals can be reset to operate in any of the six available manners depending upon the position in which said reset drum is iixed to shaft C at the particular stations. As illustrative of this, the operation of the signals at station E will be changed to the second reset and those at station F to the sixth, which extinguishes them.

It is to be understood that means for resetting the signals at particular stations is an additional feature to those shown by Figure 4, and the operations described in connection with this latter figure can be secured in addition to effecting individual resets; also individual resetting is not limited Ato only three signals; and further that more than one station can have a pin in position l, for example, on the auxiliary sequence drum thereat, whereby all of said signals so provided can be simultaneously reset under control of key 49| without disturbing the settings at the remainder of the stations. It is also to be understood that certain or all signals can be individually reset to more than one of the available manners by having other drums similar to 42lD and 458D at each station and corresponding selecting means at the central station.

It is to be still further understood that either with the embodiment of my invention as shown by Figure 4 or Figure 1l, I may elect to reset two signals or two groups of signals to two different resets by a single operation of the resetting means. This can be effected, for example, by having a pin in position 2 on drum 4l? at the rst station and in this same position on drum 41S at the second station, so that energy transmitted from the central station with the several shafts A in position 2 will result in shaft C at the rst station being moved to position 2 to make effective the second reset and shaft C at the other station to the fifth position for flashing yellow lamps. This particular combination of resets is cited as illustrative, it being obvious that any other combination could be used. Also, by extension of this principle I can reset six signals or groups thereof simultaneous to six different resets by the expedient of having the pins in the same position, say the lth, on drum 4l6 at one station, 4H at another and soon, which results in the six corresponding different resets becoming effective at the respective stations by transmitting energy with shafts A in the 'lth position.

While a twelve impulse per cycle system has been described, in practicing my invention I probably will elect to employ a greater number of impulses, in which case a larger number of signals can be reset individually. Where there is a greater number of signal stations than impulses per cycle, I may elect to group several signals at intersections having substantially the same traflic ow conditions so that they can be reset together by having the pins on drum 421 thereat in the same position. Should I desire to reset individually this larger number of stations I could provide several banks and wipers similar to 463, each with an auxiliary trunk conductor to drum contacts 42l of a group of signals. In a twelve impulse system with thirty-three signal stations, this would require three bank assemblies similar to 463, each connected to a separate trunk conductor to a group of eleven signals. Thirty-three keys similar to 87 would be required, with all of them with normally closed contacts in series with their corresponding points on bank 482, so that any one of the several, including 482, connected to point 2, for example, would open the circuit to this point, thereby stopping the selectors and the sequence drums on position 2 for individual resetting. This modication is obvious to those practiced in the arts and the detailed circuits and description thereof have been omitted.

Resetting signals individually for the off condition was assumed for the purpose of description, it being understood that any one of the resets could be individually selected in the same manner. I might elect in practicing my invention to reset certain of the signals to the idle condition during light trafc hours in which reset a iiashing amber signal in all four directions or other appropriate signal combination would be displayed by circuits through contacts of a drum similar to 3st of Figure 3, operative in the fifth reset. In smaller cities where the direction or route of travel of nre trucks in answering alarms is predetermined, I may elect to have the individual reset feature arranged to reset the signals along the route to an all red condition, with a reset drum similar to 344 eiective in the fourth reset position. Individual positioning of the reset drum would be effected by having the circuit from contacts of 42l extended to contacts of drum l5? instead of 459 as shown. In the event the individual reset feature is used for other than selectively resetting certain signals to the caution or iifh position and it is desirable to so operate a particular group of signals, I may elect to connect conductor 422 to another auxiliary trunk conductor Q4 extending to the central station, at which point an auxiliary switch 480 would be provided which would connect this last mentioned conductor to power terminal 468 when it is operated. This would cause all signals connected to this conductor to be reset to the fth or caution'position without disturbing the operation of the remainder of the signals. It is apparent that several groups of signals could be reset by having a similar auxiliary trunk conductor for each group to which they would be connected and a switch at the central station associated therewith. I am, of course, not restricted to resetting l signals to the caution condition in this manner since it is obvious that groups of signals similarly could be arranged to be reset to the off or fire condition. In so operating my invention, resetting of groups of signals by such means would be effected when the sequence drums are in positions other than i through 6, inclusive, so that none of the contacts associated therewith would be closed. I might elect to have a replica of the signal station apparatus at the central station or other means to observe the position of the sequence shaft and the operation of the system.

I could, if I so elect, extend individual circuits over auxiliary trunk conductors from the upper contacts of each of drums 454 through 459', ina elusive, to the central station, at which point keys similar to 48d connected to said trunk conductors could be selectively operated to extend power from terminal 49B to the contacts of the reset drums, causing the latter to be positioned to the reset corresponding to the operated key. Inasmuch as the arrangements for effecting this would be identical with those described above in connection with resetting groups of signals to the idle position by operation of key 480, detail circuits and description pertaining thereto have been omitted. Ii I should so practice my invention I could dispense with drums 4MB through 420, inclusive, and keys 435 through 485, inclusive. These arrangements are illustrative of the flexibility of my invention as applicable to the various traffic conditions and requirements of individual cities and towns.

The use of relays as a means of controlling local currents of relatively large magnitude by means of a small operating current flowing in the relay winding is well understood. I may elect in practicing my invention in connection with the various embodiments thereof to use relays at each signal station with their contacts com.-

pleting circuits between the local power supplies and the operating circuits of the various stepping magnets and' apparatus, and with the windings of the several relays connected to the trunk conductors to be operated by the impulses shown in the several iigures as operating the stepping magnets directly. This will greatly reduce the current flowing in the trunk conductors to permit the use of smaller gauge wire or the operation of a larger number of signals with a given size of trunk conductor. 'Ihe use of relays for such purposes is so well understood by those practiced in the art that the detailed application of them has been omitted.

The arrangements which are disclosed by Figures 3 and 4 are susceptive of various changes,

lmodification and' adaptations which I may elect to employ in practicing my invention under the wide ariety of conditions encountered in the control o traiiic in various cities. For example, the circuits to the several signal lamps are shown operated simultaneously by cam 343 for the iirst three resets. I may elect, however, to have each of these circuits controlled by a separate cam and contacts. With such an arrangement I can have the contacts of certain of the signal lamps opened in one or more of the iirst three positions of shaft C by appropriate design of said separate cam faces. That is, I can, for example, have the yellow lamps arranged to operate in the first two positions of shaft C but in the third have them omitted from the cycle. I may, further, elect to have other cams on shaft C with contacts connected to certain or all of the signal lamp circuits, which cams would be operatively eiiective in one or more of the positions of shaft C' to transfer the signal operating circuits from certain or all of drums 33! to 336, inclusive, to other drums having a diiierent pin arrangement whereby an entirely different sequence and/or combination of lamps would be lighted each cycle and/or a different number of signal elements'would be provided. In view of the means shown in detail for effecting similar operations the provision of these alternative arrangements will be obvious to those skilled in this art and drawings specically setting them forth have been omitted.

It is the practice in certain cities to have directional arrows or other traflic controlling indicators or signs which are lighted at particular parts of each cycle. I can provide this by having additional drums on shaft B with appropriately placed pins thereon to control actuating circuits therefor. t is also apparent that by extending said circuits therefor through contacts operated by cams on shaft C, I can make said arrows, indicators or signs operative for certain resets and inoperative for others. By other appropriate cams on shaft C I can, of course, make such auxiliary indicators burn continuously for certain resets. 'Ihese arrangements also will be obvious to those skilled in the art. The use of signal drum stepping and control means as shown by Figure 4 enables one set of signal drums to be arranged so that any one of a plurality of trame cycles can be secured with various numbers of phases. The signal drums shown in Figure 3 as 33! through 33E, inclusive, are, as stated above, of the same type which would be used with Figure 4. These drums provide a traiic signal cycle of six phases or elements. It might be that a smaller number of phases would be desirable, as for example the four phase type in which the yellow signal lamp is displayed in all directions for a short change period after each red and green signal display.

With the arrangements for stepping this drum shown in Figure 4, reducing the cycle from six to four phases would require changing the pins on certain of the signal drums. Only three pins would be provided on drums similar to il! 2 which control the normal stepping operation of magnet 1312. The pinon drums similar to M3 which controls the synchronization of the signal drums would have to be located to provide step-ping of the latter drums from the fourth to the first position at the proper time for the beginning of the cycle. When the pin on drum M3, for example, closes its contacts, stepping magnet 72 immediately would operate to step the signal drums on shaft B to their rst position by circuits previousl described. In the first four positions of shaft B, the signal drums 33H through 335 would have their pins arranged for the desired combination of lighted lamps for the traiiic cycle employed and with the pins in the fourth position repeated in the fifth and sixth positions. Consequently, when magnet 412 operates to move the signal drums from the fourth to the iirst position, the same signal lamp combination as prevailed in the fourth position would be continued through the fifth and sixth to the rst position. This would take a very short interval of time and I might elect to omit the pins in positions ve and six of these drums, in which case all signal lamps would be extinguished in these two positions, but in practice this would probably amount to less than a second and, therefore, would hardly be noticeable. In practicing my invention I might provide the signal drums with more than six positions, with the obvious circuit and apparatus changes to so operate them, so that cycles with various numbers of phases or elements could be secured in a particular signal system with the signal drums at each signal station identical with those at the other stations and the pins on the signe-. drums so located as to give the desired type of cycle for that signal station.

The embodiments of my invention as disclosed by Figures 1, 3 and 4 provide for rotation of shaft A and the attached sequence drums by means of stepping magnets. In practicing my invention I may elect to drive this shaft by means of a synchronous or other relatively constant speed motor such as is designated 572 in one arrangement for effecting this as shown by Figure 5. In this figure practically only that portion of the apparatus required to control the operation of shaft A and effect the reset operation is shown, it will be understood that the remainder of the signal station apparatus and circuits will be identical with that shown by Figure 4 and the correlated apparatus shown by Figure 3, with the exceptions'which will be described. At the central station three selectors 50i, 502 and 5M are shown, each has a wiper xed to a common driven by motor 5ml operating through suitable gearing, not shown.` The shaft and wipers revolve at a fixed rate of, say, one revolution per minute for purposes of explanation. Twelve contacts are shown on each bank, which number is selected only for explanation inasmuch as a greater or smaller number can be employed with my invention.

The bank contacts of 5!! are connected together and to power terminal ldt, except contact .l

i2 which is left open. Consequently a circuit is partially completed over trunk conductor N5 for all but one point of this latter mentioned bank. At each signal a motor 512 drives through suitable gearing shaft A at the same rate as the central station wipers are revolved by their motor. In position I2 drum 5H, which is attached to shaft A and corresponds in purpose to drum 41| of Figure 4, closes its contacts, which connects one side of the winding of relay 51| to trunk conductor N5, the other side being connected to the common return conductor P5 and, therefore, to power terminal 509. Relay 504 is in its operated position while this operation is taking place as will be described hereafter. Relay 51| will not operate under this condition provided shaft A and the central station wipers are in synchronism since when the contacts of 5|| are closed the wiper of 50| will be on the 12th o-r open point. If, however, shaft A gets out of synchronism relay 51| will be operated when shaft A gets to the 12th position since the operating circuit therefor described just above will be closed since the wiper of 50| will be off of the 12th position. The operation of relay 51| opens the obvious circuit by which power is supplied the driving motor 512, causing it to stop, thereby stopping the drums on shaft A in the 12th position. When wiper 50| reaches the 12th point the operating circuit of relay 51| will be opened and it will release, thereby completing the circuit to motor 512, and the central and signal station shafts again will be in synchronism.

Instead of a relay such as 51| to open the circuit to the motor I may elect to employ a clutch in the shaft between motor and shaft A, said clutch being normally in its contacted position. One arrangement for providing this is shown by Figure 6, in which a disc clutch 614 is shown with its faces normally drawn into contact by a spring. A magnet 81| with its winding connected in the same way as shown for relay 51| and substituted therefor is arranged so that when it is energized it attracts its armature and an extension thereto separates the two faces of the clutch, thereby causing shaft A to be stopped. When this magnet is deenergized the clutch faces will be forced in contact and shaft A will again be turned by the motor. The substitution of magnet 61| and the clutch arrangement for relay 5H will operate to effect synchronism in the same general manner as described above in that if shaft A reaches position I2, magnet 61| will be energized unless the wiper of 50| also is in the 12th position. If this occurs and magnet 61| is energized it will operate the clutch to stop shaft A in position l2 until the central station shaft reaches this position, at which time it will release permitting shaft A to be driven.

I may employ the same general principle and means for resetting the signals with a motor drive as shown by Figure 4. In Figure 5 relay 504 is normally operated by a circuit from power terminal 509, winding of relay 504, wiper and bank contacts of 502, switch 58| in its normal position to the other power terminal 508. It is to be understood that each point of bank 502 is connected to power terminal 508 via switch contacts or wiring, not shown, on points to which no switch is connected in the same manner as shown with respect to bank 402 of Figure 4. If it is desired to reset the signals to the first reset key 50| is operated. This opens the circuit to point of bank 502 and when the wiper reaches this point relay 504 is released, thereby opening an obvious circuit to motor 500 which stops the wipers on point I. The back contact of relay 504 extends a circuit over trunk conductor Q5 to operate relay 51| or clutch magnet 61| to stop shaft A in position l. Key 58| in its operated position extends power from terminal 508 to point of bank 503 and thence over trunk conductor O5 to contacts of drums 5|6 through 52|, inclusive, part of which are shown, which correspond to and are identical with drums 4|6 through 42|, inclusive, of Figure 4. In a manner identical with that described in connection with Figure 4 this circuit is extended through the operated contacts of drum 5|6 on shaft A via conductor 423 to cause the reset shaft C, not shown, to be stepped around to the position for the first reset. Restoration of key 58| will cause relay 504 to reoperate, thereby starting the motor at the central station and permitting relay 51| to release again to complete the circuit to motor 512, or permitting clutch magnet 61| to release if the clutch arrangement is provided. Other resets similarly can be selected, and a clutch can be used at the central station.

As stated above, the driving and synchrohizing means shown by Figure 5 is designed to be substituted for the driving and synchronizing means of Figure 4. The means for electing individual signal resets, remote shutdown and the other features set forth in connection with Figure 4 can be secured with motor driven signal apparatus as readily will be understood by those skilled in the art.

It is contemplated that synchronous motors will be used at both the central and signal stations. Inasmuch .as the alternating current power at the signal stations may be supplied from a diiferent source with a different frequency from that at the central station, by employing gears or other suitable means interposed between the motor and the sequence shafts at the signal stations this difference in frequency can be compensated for to result in the proper speed of said shafts. Other types of motors having relatively constant speed can be employed, or speed governors can be used tomaintain proper speed. In the event direct current is employed or for other reasons synchronous motors are not used, the sequence shafts can be arranged by suitable means so that they will revolve slightly faster than the central station shaft so that in normal operation they will stop for a short interval in the synchronizing position once each cycle to compensate for a possible slight downward variation in speed, If a signal station shaft A reaches the synchronizing point just .after the central station wipers have advanced to position l, the signal operation at that particular station would be stopped for substantially a complete cycle, whereas with a sufliciently greater speed of the signal shafts with respect to the central station shaft to care for minor variations in speed, the signals would not he stopped except for a relatively short and insignificant time each cycle. If other than synchronous motors are employed, it may also be necessary to employ wide contact pins on drums 5|0 to 52|, inclusive, or other appropriate means, to 4assure that the proper contacts in connection with said drums are operated in a particular reset position notwithstanding slight variations of speed. It may also be necessary in such event to space the reset pins on said drums further apart than contemplated with a synchronous motor system to prevent variation of speed causing an improper reset contact being closed.

Varying the length of the total cycle where the rheostat or other appropriate means, or by employing change speed gearing between a constant speed motor and shaft D, or the interrupter. The arrangement shown in Figure 5 contemplates that the central and signal station motors will run at such speed as to drive their respective shafts at the same relative speed, giving consideration to the fact that the use of double ended wipers requires the central station shaft will be driven at half the speed of the signal station shaft. In order to vary the overall cycle I propose to interpose between the motor 512 and shaft A electrically operative speed change gearing designated as 511. One design of such gearing to effect the proposed result is shown by Figure 7. The shaft from the motor is designated 101 and ts in a hollow cylinder 111, having a plurality of rings arranged longitudinally as shown. This cylinder is keyed to shaft 101 but can be moved longitudinally .along it by means of two electrically operated pawls. Pawl 118 is operated by the energization of magnet 518 to step cylinder '111 one position to the left, one position representing the distance between corresponding points on two successive rings on 'the cylinder. Repeated operation of magnet 518 will repeatedly step the cylinder to the left until the limit of its travel is reached. Likewise, operation of magnet 519 will cause its pawl to step the cylinder 111 to the right. As will be described below, these magnets are operative from the central station to move the cylinder to any one of its desired positions. A spring maintains cylinder 111 in the position td which it is stepped by magnets 518 and 519.

A gear pinion 109 is attached to shaft 'H3 which, in turn, is. attached to cylinder '111 and n consequently is moved longitudinally by and revolves with said cylinder. Shaft 102 is an extension of shaft A to which the sequence drums are attached. A shaft '120 is connected to shaft 152 by means of a flexible or universal joint 153. The other end of shaft 12D has a collar affixed thereto and a spring 111 operating in conjunction therewith tending to pull shaft 125 in an upward direction. Keyed to this shaft are four gear wheels or pinions '104, 105, 1915 and 191, each of different diameter from the others. The spaces between these wheels are filled by members having the general shape of frustrums of cones. Gear wheel 199 is shown meshed with gear wheel 105, and consequently driven shaft 102 revolves at a speed with respect to shaft 101 as determined by the diameters of the gear wheels, as is well known. If it is desired to reduce the speed of shaft 192, magnet 518 is operated which causes its pawl to move the cylinder '111, shaft 113 and gear wheel '109 one position to the left. As the gear wheel moves out of mesh with wheel 105 it encounters the intervening spacer. Due to the universal joint and the fact that shaft 120 operates in a slot in the left hand portion of the frame, this movement of 109 will force shaft 120, together with its several gear wheels, downward as it moves to the left along the intervening conic spacer until it meshes with gear wheel 106 at the end of its travel. The speed of shaft '102 now will be determined by the relation of diameters of gear wheels 100 and 109. Any one of the four gears can be selected in this manner by selectively operating magnets 598 and 599. I may elect to use a greater or smaller number of gears in practicing my invention than the four shown by Figure '1.

The operation of the circuits and apparatus in Figure 5 is premised on the central and signal station shafts' revolving at the same speed. A speed change gear mechanism such as shown by Figure 7 will also be interposed between motor 500 and shaft D so that the same change of speed of the sequence shafts at the signal stations will be effected for shaft D. A switch 506 is provided which can be moved to close either contact a or b. If it is desired to increase the speed of the central and signal station shafts and thereby reduce the overall time for a complete traffic cycle, switch 506 is moved to close contact b for a short interval which will extend a circuit from power at terminal 508, contact b to a junction, part of the current flowing through magnet 519 to the other power terminal 509, and the remainder out over trunk conductor T5, winding of magnet 519 to the other power terminal 589 via common return trunk conductor P5. The operation of magnets 519 and 519 will cause gear 109 to be moved into mesh with gear 104 of the respective gear change mechanisms of Figure 7 located at the signal and central stations. Likewise the overall period of the signal cycle can be increased in a similar manner by moving switch 5115 to close contact a, thereby energizing magnets 518 and 518', resulting in gear wheel 109 being moved to the left. In this manner the overall period of the traffic cycles can be controlled from the central station.

With motor driven signal station apparatus, a serrated drum or disc can be provided either on shaft 'A or on a constant speed shaft driven by the motor with associated contacts to furnish flashing impulses for flashing signal operation with certain of the resets.

Contacts and 116, shown in Figure 7, can be closed by the extension 114 of shaft 119, if the latter is moved to the left beyond the last gear meshing position. Since the movement of shaft 113 is controlled from the central station by means described above, I may elect to employ these and other similarly located contacts as an alternate means to select the reset in which the signals are to be operated. Figure 8 shows one arrangement for effecting this in connection with the embodiment of my invention shown by Figure 5. If it is desired to reset the signals to the off position, shaft 113 will be moved to close contacts 115 by the above described means, including switch 505 at the central station. Contacts 1&6 are shown in Figure 8, and with them closed the operation of switch 801 at the central station will extend power from terminal 509, a trunk conductor, contacts '116, the contacts of drum 159, the back contact of stepping magnet 413, common trunk conductor P4 to the other power terminal 409. Under this condition the stepping magnet will repeatedly operate to move the reset shaft C and the drums thereon to the 6th position, at which point the contacts of 459 will be opened. Drum 459 and stepping magnet 413 are shown in Figure 4 and by these means the reset drums will be moved to disconnect the signals from the power terminal. Likewise, by employing five other contacts such as 116 selectively operable from the central station by longitudinal movement of shaft '113 and'similar means, including drums 454 through 459, any of the six resets can be selected. It is to be understood that with this method of reset selection I may elect not to employ drums 415 through 420, inclusive, or keys 481 through 486, inclusive, shown in Figure 4, and would make the other obvious minor circuit changes incident to their omission.

The use of special means for effecting a plurality of independent remote operations over a single pair of wires are widely used in various of the arts. One of these is disclosed by the Wensley Patent No. 1,786,805 whereby carrier currents of different frequencies operate corresponding frequency responsive means to effect individual remote circuit control. The use of such arrangements is an obvious expedient which I may elect to employ in order to reduce the number of conductors between the central and remote stations of my system.

This invention has been illustrated and described in connection with a system for operating street traiiic signals. However, itis understood that the apparatus and principles of operation disclosed are applicable to other signal and selector systems. It is also to be understood that the particular arrangements provided and results effected thereby in particular embodiments of my invention can, as appropriate and in a manner understood by those practiced in the arts, be applied to other embodiments of my invention. It is also further to be understood that the apparatus per se or the respective sub-systems per se, in contradistinction to the disclosed system as a whole, may be used separately to accomplish the functions contemplated thereby without departing from the spirit and scope of the invention.

What is claimed is:

l. In combination, an electrical energy Vtranstransmitter, electrical devices, cyclic circuit controlling means; means to operate said devices cyclically at predetermined times during each cycle; energy responsive means to selectively control last said means; electrical circuit connecting means between said energy responsive means and said cyclic circuit controlling means; means to cause said devices to be operated in another predetermined manner, last said means including means to cause said energy transmitter to transmit energy with said circuit controlling means in a particular part of its cycle, said circuit connecting means and said energy responsive means.

2. In combination, an electrical energy transmitter, electrical circuits, a cyclical circuit actuator; circuit controlling means; means including said circuit actuator and said circuits to operate said circuit controlling means intermittently at predetermined times in repeated cycles; circuit operated electrical devices variably operated by said circuit controlling means, the intermittent cyclical operation of said circuit controlling means causing said devices to be operated cyclically at predetermined times in each cycle; energy responsive means to selectively control the operation of said circuit controlling means; means to cause said devices to be operated in another predetermined manner, last said means including means to cause said energy transmitter to transmit energy at a particular part of the cycle of said circuit actuator and said energy responsive means.

3. In combination, a circuit controller, means to operate said controller cyclically; a second controller, means to operate said second controller intermittently in predetermined cycles by said first controller; electrical devices; means to operate said devices by said second controller in response to the intermittent cyclical operation thereof to result in said devices being operated cyclically at predetermined times in each cycle; an electrical energy transmitter; energy responsive means to control the operation of said devices; circuit connecting means between said en'- ergy responsive means and iirst said controller; means to cause said devices to be operated in any one of a plurality of other predetermined manners, last said means including means to cause said energy transmitter to transmit energy with said iirst controller in a part of its cycle corresponding to the particular manner of operation, said circuit connecting means and said energy responsive means.

4. In combination, electrical energy transmitting means, three circuit controlling means; means to operate the rst of said circuit controlling means cyclically, means including said first circuit controlling means to operate said y second circuit controlling means at predetermined times in repeated cycles, energy responsive means to selectively operate said third circuit controlling means; circuit connecting means between said first circuit controlling means and said energy responsive means; a plurality of electrical devices, electrical circuits connecting said devices with said third circuit controlling means and electrical circuits connecting said third circuit controlling means With said second circuit controlling means whereby said devices are operated cyclically over said circuits at predetermined times in each cycle by said second circuit controlling means; means to operate said devices in another predetermined manner, last said means including means to cause energy to be transmitted in a particular part of the cycle of said first mentioned circuit controlling means, said circuit connecting means, said energy responsive means and said third circuit controlling means; means to discontinue the operation of said devices, last said means including means to cause energy to be transmitted in another particular part of the cycle of said first mentioned circuit controlling means, said circuit connecting means, said energy responsive means and said third circuit controlling means.

5. In a control system, a first station, a second station, circuit connections between said stations, cyclical circuit closing means at said iirst station, energy transmitting means at said iirst station; electrical devices at said second station, means at said second station to operate said devices cyclically at predetermined times in each cycle; energy responsive means at vsaid second station selectively operable to control last said means; means to cause said devices to be operated in another predetermined manner, llast said means including means to cause energy to be transmitted over said circuit connections with said circuit closing means in a particular part of its cycle and said energy responsive means.

`6. In a control system, a first station, electrical impulse transmitting means thereat, a second station, circuit connections between said stations, cyclical circuit controlling means at said second station, electrical devices at said second station, means to operate said devices at particular times in repeated predetermined cycles, impulse responsive means to selectively control last said means, circuit connecting means between said circuit controlling means and said impulse responsive means, means to operate said devices in another predetermined manner, last said means including means to cause an impulse to be transmitted from said first station to said second station over said circuit connections at a particular time during the cycle of said circuit controlling means, said circuit connecting means and said impulse responsive means.

'7..In a control system, a central station, cyclical circuit closing means thereat; electrical energy transmitting means cooperating with said circuit closing means; a remote station and electri'cally operated devices thereat; circuit connections between said stations; cyclically operated selecting means at said remote station, means including said circuit connections to cause saidV circuit closing means and said selecting means to operate in synchronism; means at said remote station to operate said devices cyclically at predetermined times in each cycle; energy responsive means variably operable -depending on the part of the cycle said selecting means is in when energy is received to selectively control the operation of said devices; means to operate said devices in a particular one of a plurality of other predetermined manners, last said means including means to cause said energy transmitting means to transmit energy over said circuit connections at a particular time in the cycle of operations of said circuit closing means corresponding to the particular manner of operation, said selecting means, and said impulse responsive means.

8. In a control system, a iirst station, electrical energy transmitting means thereat; a second station, electrical devices thereat; energy conducting medium between said stations; cyclical circuit closing means at said second station; electrical devices at said second station, an operating circuit for each device, circuit controlling means for each of said circuits to operate the corresponding device; means to operate said circuit controlling means individually in a plurality of diiierent predetermined manners, one of said plurality of manners resulting in particular ones of said devices being operated at particular times in predetermined cycles and another of said plurality of manners resulting in particular ones of said devices being discontinued from operation; energy responsive means to selectively control the operation of said circuit controlling means; electrical circuit connecting means between said circuit closing means and said energy responsive means; means to operate said circuit controlling means in any particular one of said plurality of predetermined manners, last said means including means at said rst station to cause said energy transmitter to transmit energy over said conducting medium to said second station with said circuit closing means in a particular part of its cycle corresponding to the particular manner of operation of said circuit controlling means,

said circuit connecting means between said circuit closing means and said energy responsive means, and said energy responsive means.

9. In a control system, a iirst station, a second station, circuit connections between said stations,

Y, cyclically operated selecting means at said second station, means including said circuit connections to stop said selecting means in particular parts of the cycle thereof; electrical devices at said remote station, means to operate said I devices at particular times in predetermined cycles; means functioning selectively depending upon the part of the cycle in which said selecting means is stopped to control the operation of said devices; means to operate said devices in another predetermined manner, last said means including means to stop said circuit controlling means in a particular part of its cycle and said device controlling means.

10. In a control system, a central station, a plurality -of remotely disposed stations, circuit connecting meansy between said central station and said remote stations; means at said central station selectively operable to transmit electrical energy over said circuit connecting means to saidvremote stations; cyclical circuit controlling means at each of said remote stations; means to operate said circuit controlling means at said remote stations insynchronism with each other; electrical devices kat rsaid remote stations; means to operate said devices at each station at particular times in predetermined cycles; energy responsive means at each remote station to selectively control the operation of said devices thereat; means to cause said devices at said remote stations to be operated in another manner predetermined individually for each remote station, last said means including said means at said central station operated to transmit energy over said circuit'connecting means to said remote stations with said circuit controlling means thereat/in a particular part of the cycle thereof and said energy responsive means thereat.

11.In a control system, a central station, a plurality of remote stations, circuit connecting means between said central station and said remote stations, means at said central station selectively operable to transmit electrical energy over said circuit connecting means to said remote stations; cyclically operated selecting means at each of said remote stations; means to operate said selecting means at said plurality oi remote stations in synchronism with each other; electrical devices at said remote stations; means to operate said devices at each station at particular times in predetermined cycles, last said means including said selecting means; energy responsive means at each remote station to selectively control the operation of said devices thereat; means to cause said devices at particular ones of said remote stations to be operated in another manner predetermined individually for each particular remote station, last said means including said means at said central station operated to transmit energy over said circuit connecting means to said remote stations with said selecting means thereat in a particular part of their cycle and said energy responsive means thereat.

12. In a control system, a central station, a plurality of remotely disposed stations, circuit connecting means between said central station and said remote stations; means at said central station selectively operable to transmit electrical energy over said circuit connecting means to said remote stations; cyclical circuit closing means at each of said remote stations to effect circuit closures at particular parts of the cycle thereof, said parts predetermined individually for each remote station;I means to operate said circuit closing means at said remote stations in synchronismv with each other; electrical devices at said remote stations; means to operate particular ones of said devices at each station at particular times in predetermined cycles; energy responsive means to selectively control the operation of said devices depending upon the parts of the cycle said lcircuit closing means are in when energy is received; means to operate particular ones of said devices at particular remote stations in another manner predetermined individually for each particular remote station, last said means including said means to cause energy to be transmitted over said circuit connections with said circuit closing Vmeans at said remote 

